#include <stdio.h>
int main()
{
	int n,a[100][100];
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<n;j++)
		{
			scanf("%d",&a[i][j]);
		}
	}
	int row=0,col=0,direction=1;
	for(int i=0;i<n*n;i++)
	{
		
			printf("%d ",a[row][col]);
			if(direction==1)
			{
				if(col==n-1)
				{
					row++;
					direction=-1;
				}
				else if(row==0)
				{
					col++;
					direction=-1;
				}
				else
				{
					row--;
					col++;
				}
			}
			else
            {
	            if(col==0)
	            {
	            	row++;
	            	direction=1;
				}
				 else if(row==n-1)
				{
					col++;
					direction=1;
				}
				else
				{
					row++;
					col--;
				}
	
			}			
		
	}
	return 0;
}
